| Exploring syntactic structured features over parse trees for relation extraction using kernel methods Recent countries visiting this post |  |
 | 5 | United States |
 | 2 | |
 | 1 | China |
 | 1 | Canada |
 | 1 | Japan |
| Exploring syntactic structured features over parse trees for relation extraction using kernel methods Recent countries visiting this post | |
| 5 | United States |
| 2 | |
| 1 | China |
| 1 | Canada |
| 1 | Japan |